The present invention refers to a sealing device for bearings with an integrated encoder for detecting relative rotation between the races of a bearing unit.
Sealing devices fitted at the sides of a bearing unit in order to seal the gap between the bearing races are well known. Generally, these sealing devices are comprised of a metal reinforcing insert of disc-annular shape onto which there is over-moulded or vulcanized a gasket made of rubber or soft elastomeric material forming two peripheral sealing portions: an outer peripheral portion mounted on the stationary outer race of the bearing in order to perform a static sealing action against this race, and an inner peripheral portion with one or more dynamic sealing lips for sliding against the inner, rotatable bearing race.
U.S. Pat. No. 5,383,728 discloses a sealing device of the above-mentioned type wherein the conventional metal insert is replaced by a rigid annular insert of plastic polymeric material.
There are also known sealing devices for bearings incorporating a magnetic impulse ring or encoder fixed to a protective metal shield mounted on the rotatable bearing race. See, for example, U.S. Pat. No. 6,776,420. In use, the impulse ring faces a fixed sensor which detects the relative speed of rotation between the outer and inner bearing races.